July's home sales fell 1.7% in July to a seasonally adjusted annual rate of 4.06 million and were worse than economists' expectations. Commodity traders seemed to see it coming.

Lumber prices, as measured by the Random Lengths Framing Lumber Composite, a gauge of spot-market sales, hit their highest level in four years late last month on reduced supply due to mill closures and fewer imports. Around then, traders started dumping lumber futures, betting that higher mortgage rates would slow homes sales, which in turn means fewer remodeling jobs and less wood demand.

Lumber futures for September delivery shed more than 12% over roughly two weeks starting in late July. Futures have ticked slightly higher during the past few trading sessions. Yet analysts say lumber prices have probably peaked for the year now that the bulk of the summer home-selling season is past.

Read more about how sawmill closures and reduced imports lifted lumber prices this year: